Corynebacterium macginleyi isolated from urine in a patient with a permanent bladder catheter

Ocular Bacterial Infections: A Ten-Year Survey and Review of Causative Organisms Based on the Oklahoma Experience

Ocular infections can be medical emergencies that result in permanent visual impairment or blindness and loss of quality of life. Bacteria are a major cause of ocular infections. Effective treatment of ocular infections requires knowledge of which bacteria are the likely cause of the infection. This survey of ocular bacterial isolates and review of ocular pathogens is based on a survey of a collection of isolates banked over a ten-year span at the Dean McGee Eye Institute in Oklahoma. These findings illustrate the diversity of bacteria isolated from the eye, ranging from common species to rare and unique species. At all sampled sites, staphylococci were the predominant bacteria isolated. Pseudomonads were the most common Gram-negative bacterial isolate, except in vitreous, where Serratia was the most common Gram-negative bacterial isolate. Here, we discuss the range of ocular infections that these species have been documented to cause and treatment options for these infections. Although a highly diverse spectrum of species has been isolated from the eye, the majority of infections are caused by Gram-positive species, and in most infections, empiric treatments are effective.

Corynebacterium macginleyi in the era of MALDI-TOF MS: epidemiology, susceptibility patterns and prevalence of co-infection

Corynebacterium macginleyi has long been associated with ocular infections and has more recently been rarely implicated in systemic infections. There is a paucity of literature regarding the rate of C. macginleyi co-infection with other bacterial and viral pathogens and regarding the incidence of C. macginleyi infection in the paediatric population. In this study, we report 30 isolates of C. macginleyi of ocular origin from 26 patients, identified using matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS). The rates of co-isolation with bacterial and viral pathogens were 62% (n=16/26) and 39% (n=5/13), respectively, in this study. Of these, 13 patients had molecular testing performed as requested by treating clinicians for either the Chlamydia trachomatis/Neisseria gonorrhoeae PCR or herpes/enterovirus/adenovirus multiplex PCR. All isolates tested susceptible to linezolid, vancomycin and ciprofloxacin, with variable resistance to tetracycline, clindamycin and penicillin using EUCAST breakpoints.

Clinical and genomic features of Corynebacterium macginleyi-associated infectious keratitis

Infectious keratitis is a potentially sight threatening ophthalmological emergency. Contact lens wear is a common risk factor. Diagnostic advances such as MALDI-TOF MS provides new insights into the spectrum of corneal pathogens and on microbes previously considered as commensals. Corynebacterium macginleyi was described in 1995, and in 2018, the genomic features of three isolates were reported after whole-genome sequencing. Here we describe the clinical characteristics of patients with infectious keratitis (n = 29) presumably caused by Corynebacterium macginleyi, and analyze the genomic features of C. macginleyi (n = 22) isolated from the corneal ulcers of these patients. The disease course was uneventful apart from minor interventions such as corneal cross-linking and amniotic membrane transplant. Genome sequencing and comparison revealed a highly conserved core genome of C. macginleyi. Based on the analyses of single nucleotide polymorphisms, the population could be divided into two main clades that also differed in a few clade-specific genomic islands. Patients infected with an isolate belonging to the minor clade (n = 7) presented a more severe disease. Comparisons with other corynebacterial species clearly separated C. macginleyi. C. macginleyi may be considered a corneal pathogen; genomic analysis provided insights into its population structure and disease-causing potential.

Current Evidence for Corynebacterium on the Ocular Surface

Corynebacterium species are commonly found in the conjunctiva of healthy adults and are recognized as non-pathogenic bacteria. In recent years, however, Corynebacterium species have been reported to be potentially pathogenic in various tissues. We investigated Corynebacterium species on the ocular surface and reviewed various species of Corynebacterium in terms of their antimicrobial susceptibility and the underlying molecular resistance mechanisms. We identified a risk for Corynebacterium-related ocular infections in patients with poor immunity, such as patients with diabetes or long-term users of topical steroids, and in those with corneal epithelial damage due to trauma, contact lens wear, lagophthalmos, and trichiasis. The predominant strain in the conjunctiva was C. macginleyi, and the species associated with keratitis and conjunctivitis were C. macginleyi, C. propinquum, C. mastitidis, C. pseudodiphtheriticum, C. accolens, C. striatum, C. xerosis, and C. bovis. Overall, Corynebacterium species present on the ocular surface were resistant to quinolones, whereas those in the nasal cavity were more susceptible. The prevalence of fluoroquinolone-resistant Corynebacterium has not changed in the past 10 years; however, Corynebacterium species remain susceptible to third-generation cephems. In conclusion, the use of third-generation cephems should be a reasonable and pragmatic approach for treatment of ocular infections caused by Corynebacterium species.

Corynebacterium macginleyi-associated Blebitis: A Case Report

PURPOSE

The purpose of this study was to report a rare case of posttrabeculectomy bleb-related infection associated with Corynebaterium macginleyi, a rare conjunctival pathogen.

METHODS

Case description including clinical imaging and microbiology data, and literature review of Corynebacterium macginleyi-related infections.

RESULTS

A 60-year-old glaucomatous female patient presented with a bleb-related infection 6 years after trabeculectomy in her right eye, suggestive of blebitis. No bleb-related endophthalmitis was reported.

CONCLUSIONS

C. macginleyi is a rare conjunctival pathogen that can cause conjunctivitis and, rarely, bleb-related infections.

Corynebacterium macginleyi: A cause of ventilator associated pneumonia in an immunocompromised patient

Purpose and Importance

Corynebacterium macginleyi, a lipophilic diphtheroid from the genus Corynebacteria, is a known cause of conjunctivitis. It was recently reported as a cause of serious infections in immunocompromised individuals. It has never been reported as a cause of ventilator-associated pneumonia, that which carries a high burden and risk of mortality. Our report intends to increase awareness of a potentially lethal nosocomial bacterial infection.

Observations

This case reports on a 73 year old lady with metastatic lung adenocarcinoma on chemotherapy, who was hospitalized for dyspnea and diffuse pulmonary infiltrates in 2011. Trans-bronchial biopsies revealed cryptogenic organizing pneumonia. The patient improved with steroids. Failure to wean ensued with a bronchopleural fistula, increase in secretions, oxygen requirements, and appearance of new infiltrates. Two mini-BAL cultures yielded gram positive pleomorphic rods with palisade arrangement, diagnosed as C. macginleyi. Vancomycin therapy was initiated. She improved and was successfully extubated.

Conclusion and relevance

Non-diphtheria Corynebacteria usually form normal flora. If isolated, they are often dismissed as contaminants. C. macginleyi has emerged as a life-threatening nosocomial infection. Prompt identification and treatment are required. It is resistant to quinolones. Thus far, vancomycin is the preferred treatment.

Surgical Site Infection by Corynebacterium macginleyi in a Patient with Neurofibromatosis Type 1

Corynebacterium (C.) macginleyi is a gram positive, lipophilic rod, usually considered a colonizer of skin and mucosal surfaces. Several reports have associated C. macginleyi with ocular infections, such as conjunctivitis and endophthalmitis. However, even if rare, extraocular infections from C. macginleyi may occur, especially among immunocompromised patients and patients with indwelling medical devices. We report herein the first case of surgical site infection by C. macginleyi after orthopaedic surgery for the correction of kyphoscoliosis in a patient with neurofibromatosis type 1. Our patient developed a nodular granulomatous lesion of about two centimetres along the surgical scar, at the level of C4-C5, with purulent discharge and formation of a fistulous tract. Cervical magnetic resonance imaging showed the presence of a two-centimetre fluid pocket in the subcutaneous tissue. Several swabs were collected from the borders of the lesion as well as from the exudate, with isolation of C. macginleyi. The isolate was susceptible to beta-lactams, cotrimoxazole, linezolid, and glycopeptides but resistant to quinolones, third-generation cephalosporins, and erythromycin. Two 30-day courses of antibiotic therapy with amoxicillin/clavulanate (1 g three times/day) and cotrimoxazole (800/160 mg twice a day) were administered, obtaining a complete healing of the lesion.

Corynebacterium macginleyi conjunctivitis in Canada

This report describes for the first time Corynebacterium macginleyi as a cause of conjunctivitis in Canada, where menaquinone analysis was done as part of the strain characterization. This species is typically isolated from ocular surfaces of patients from Europe and Japan. The isolate was resistant to erythromycin and clindamycin.

Suture-related keratitis caused by Corynebacterium macginleyi

We report two cases of suture-related keratitis following penetrating keratoplasty. In both cases, Corynebacterium macginleyi was isolated from corneal specimens. Scanning electron microscopy revealed that corynebacteria could aggregate and form a biofilm. The MICs of sulbenicillin and fluoroquinolones were high for both isolates. Our findings show that C. macginleyi can cause keratitis with biofilm formation.

Postoperative Corynebacterium macginleyi endophthalmitis

A 72-year-old man with chronic endophthalmitis who received steroid treatment for 3 months came to our center. Sterile endophthalmitis after cataract extraction had been diagnosed. Aqueous samples including smears, classic cultures, and polymerase chain reaction were taken for microbiological study. Amplified DNA was sequenced to identify the pathogen. Polymerase chain reaction amplification was positive for bacteria. Sequence analysis showed Corynebacterium macginleyi as the causal agent in 48 hours. The culture and smear stains from the ocular samples were negative. The patient was successfully treated with vancomycin. Polymerase chain reaction and subsequent DNA-typing were useful in detecting the microorganisms that caused the chronic endophthalmitis.